Process of forming welt shoes



July 28, 1942. G. E. MUSEBECK I PROCESS OF FORMING WELT SHOES Filed Nov. 14, 1940 atent Juiy 28, 12

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.1 OF FORMING WELT SHOES George E. llduseheck, Danville, 1ll., assignor to ldusek Shoe Sommny, Danville, lit, a coraeration 1 Claim.

This invention relates to a process of forming a welt shoe. v

In orthopedic shoes and in any type of shoe, it is important that the inner surface of the insole retain as long as While the shape of the last on which the shoe is made. This is articularly true in the case of orthopedic shoes, in the manufacture of which the lasts are carefully shaped to provide particular orthopedic results. The shank stiifeners commonly used in modem shoes are provided with corrugations to give the necessary combination of lightness and strength. Such irregularly surfaced stiifeners placed immediately beneath an insole provide a very faulty surface for supporting the insole since there is a tendency for the insole to collapse into the corrugations of the stiffener and into the spaces left at either side of the stiffener between the insole and the outsole. The effect of repeated applications of the body weight especially on an insole moistened by perspiration and supported on such a faulty surface is to cause a failure of the insole which eventually destroys the original correspondence between the weight bearing surface of the insole and the last.

Even where corrugations in the shank stiffenerS are not used, the shape of the shank stiffener seldom conforms exactly to the shape of the last so that the shoes when worn for some time assume the shape of the stifiener rather than the shape of the last. The lack of correspondence between the shank stiffener shapes and lasts is due to the fact that approximately 160 difierent sizes and widths of lasts are required for a complete line of women's shoes alone, whereas commercial production methods dictate the use of only four or five shapes and sizes of shank stifiener.

The present invention has for its principal object a shoe construction in which the insole is rigidly supported in. conformity to the original lasted contour irrespective of corrugations in the shank stifi ener, irrespective of differences be tween the shape of the stifiener and that of the last and independent of cavities normally occurring between the outsole and the insole at the edges of the stifiener. This result is accomplished by embedding the stifiener in a plastic material adapted to harden, as distinguished from the usual resilient ground cork fillers often used in Goodyear welt shoes with or without shank stiffeners. The hardened filler provides a smooth surface rigidly supporting the insole in its original curvature as determined by the last. This is seat where a roughened inner surface due to collapse of the insole is most apt to occur and is most uncomfortable.

Other objects and features of the invention and the full nature thereof will be apparent from the following detailed specifications and the attached drawing in which a preferred form of the invention is specifically described in detail:

Fig. 1 is a bottom view of a shoe in process of construction in accordance with a preferred form of the invention. Fig. 2 is a similar view at a further point in the process of manufacture. Fig. 3 is a. sectional view of a completed shoe taken on a line corresponding to line 3-3 of Fig. 2.

In Figs. 1 and 2 there is shown an insole l0 to which there has been secured the usual welt H and upper II. In the heel portion the edges of the upper have been folded about the insole and secured thereto in the usual manner. With the shoe in this stage of construction and still on the last, a quantity of a plastic filling material adapted to harden is placed on the insole in the area l3 indicated by stippling. The material preferably employed is sawdust mixed with an adhesive such as the pyroxylin cement used in other steps in shoe making and known as fcompo". This material when hardened provides a rigid structure similar in strength and rigidity to solid wood. Preferably a layer oneeighth to three-sixteenths of an inch in thickness is used.

While the filler is still in a plastic condition, a shank stiffener M, which may be of any common form, is pressed into the material with sufficient force so that corrugations and other irregularities in the surface of the stiflener are filled with the plastic material. The stiffener may be secured by tacks it in the usual manner. The plastic material is then. permitted'to harden and for this purpose heat may be applied if desired. In some cases another layer of plastic material is then applied outside of the shank stiffener and is properly shaped to conform to the desired upper surface of the outsole. In certain cases where metatarsal arch support is particularly desired; extra thickness of the filler is applied outside the shank stiffener in the metatarsal region.

The outsole it is then applied to the shoe in the usual manner after the last application of the plastic material has been peimitted to harden. In the resulting construction the irregulari-' ties of the upper surfaceof the shank stiffener particularly important in the region of the heel it are filled by the hardened fillin r l (Fig. 3) which rigidly supports the insole III in a position determined by the original shape of the last and not by the shape of the shank stiffener. The spaces l8 between the insole around the edges of the shank stlfl'ener are also filled with the rigid supporting material so that there is no tendency for the insole to collapse into such spaces. This is particularly important in the heel seat where a considerable gap is usually present at the point I9 between the shank stiffener and the inturned edges of the upper II.

The invention has been described in one of its preferred forms, the details of which may be 'varied by those skilled in the art without departing urom the scope of the appended claim.

The invention claimed is: The process of forming a rigid shoe shank in a shoe, comprising the steps of applying a filling or sawdust bound with pyroxylin shoemakers cement to the heel seat and shank of the bottom of the insole while on the last and with the filling extending iorward at least to the break line of the shoe, pressing a corrugated stiflener of less length and breadth than said filling layer part way into said plastic filling while said filling is still sufilcientlysoit to fill the corrugations in said stiffener and to coverthe ends and edges or said stiflener, and allowing said material to harden, whereby said' filling conforms to the shape or the shoe shank and rigidly retains and supports said stiffener therewith irrespective of 4 l5 irregularities in the shape of said shank stiffener.

GEO GE E. MusEBncK. 

